audio/mp3: Start implementing

audio/mp3/decode.go

@@ -0,0 +1,60 @@
+// Copyright 2017 The Ebiten Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package mp3 provides MP3 decoder.
+//
+// This package is very experimental.
+package mp3
+
+import (
+	"bytes"
+
+	"github.com/hajimehoshi/ebiten/audio"
+)
+
+type Stream struct {
+	inner *bytes.Reader
+}
+
+// Read is implementation of io.Reader's Read.
+func (s *Stream) Read(p []byte) (int, error) {
+	return s.inner.Read(p)
+}
+
+// Seek is implementation of io.Seeker's Seek.
+func (s *Stream) Seek(offset int64, whence int) (int64, error) {
+	return s.inner.Seek(offset, whence)
+}
+
+// Read is implementation of io.Closer's Close.
+func (s *Stream) Close() error {
+	return nil
+}
+
+// Size returns the size of decoded stream in bytes.
+func (s *Stream) Size() int64 {
+	return int64(s.inner.Len())
+}
+
+func Decode(context *audio.Context, src audio.ReadSeekCloser) (*Stream, error) {
+	var buf bytes.Buffer
+	if err := decode(src, &buf); err != nil {
+		return nil, err
+	}
+	s := &Stream{
+		inner: bytes.NewReader(buf.Bytes()),
+	}
+	// TODO: Resampling
+	return s, nil
+}

audio/mp3/decode_notjs.go

@@ -0,0 +1,108 @@
+// Copyright 2017 The Ebiten Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build !js
+
+package mp3
+
+// #include "pdmp3.h"
+import "C"
+
+import (
+	"errors"
+	"io"
+	"unsafe"
+)
+
+const (
+	eof = 0xffffffff
+)
+
+var (
+	reader      io.Reader
+	readerCache []uint8
+	readerPos   int
+	readerEOF   bool
+	writer      io.Writer
+)
+
+//export Get_Byte
+func Get_Byte() C.unsigned {
+	for len(readerCache) == 0 && !readerEOF {
+		buf := make([]uint8, 4096)
+		n, err := reader.Read(buf)
+		if err != nil {
+			if err == io.EOF {
+				readerEOF = true
+			} else {
+				panic(err)
+			}
+		}
+		readerCache = buf[:n]
+	}
+	if readerEOF {
+		return eof
+	}
+	b := readerCache[0]
+	readerCache = readerCache[1:]
+	readerPos++
+	return C.unsigned(b)
+}
+
+//export Get_Bytes
+func Get_Bytes(num C.unsigned, data *C.unsigned) C.unsigned {
+	s := C.unsigned(0)
+	for i := 0; i < int(num); i++ {
+		v := Get_Byte()
+		if v == eof {
+			return eof
+		}
+		*(*C.unsigned)(unsafe.Pointer(uintptr(unsafe.Pointer(data)) + uintptr(i)*unsafe.Sizeof(s))) = v
+	}
+	return C.OK
+}
+
+//export Get_Filepos
+func Get_Filepos() C.unsigned {
+	if len(readerCache) == 0 && readerEOF {
+		return eof
+	}
+	return C.unsigned(readerPos)
+}
+
+//export writeToWriter
+func writeToWriter(data unsafe.Pointer, size C.int) C.size_t {
+	buf := C.GoBytes(data, size)
+	n, err := writer.Write(buf)
+	if err != nil {
+		panic(err)
+	}
+	return C.size_t(n)
+}
+
+func decode(r io.Reader, w io.Writer) error {
+	reader = r
+	writer = w
+	for Get_Filepos() != eof {
+		if C.Read_Frame() == C.OK {
+			C.Decode_L3()
+			continue
+		}
+		if Get_Filepos() == eof {
+			break
+		}
+		return errors.New("mp3: not enough maindata to decode frame")
+	}
+	return nil
+}

audio/mp3/pdmp3.h

@@ -0,0 +1,23 @@
+#ifndef PDMP3_H
+#define PDMP3_H
+
+#include <stddef.h>
+
+//#define DEBUG
+#define IMDCT_TABLES
+#define IMDCT_NTABLES
+#define POW34_ITERATE
+#define POW34_TABLE
+#define OUTPUT_RAW
+
+#define OK    0
+#define ERROR -1
+
+unsigned Get_Byte(void);
+unsigned Get_Bytes(unsigned num, unsigned* data_vec);
+unsigned Get_Filepos(void);
+int Decode_L3(void);
+int Read_Frame(void);
+size_t writeToWriter(void* data, int size);
+
+#endif

examples/_resources/audio/license.md

@@ -17,6 +17,14 @@ http://mart.kitunebi.com/music_act.html
 Harpie's Feather (ハルピュイアの羽) by Napi
 ```
 
+## game2.mp3
+
+```
+http://mart.kitunebi.com/music_act.html
+
+ノアの羽舟 by Napi
+```
+
 ## ragtime.ogg
 
 ```

examples/audio/main.go

@@ -25,7 +25,7 @@ import (
 
 	"github.com/hajimehoshi/ebiten"
 	"github.com/hajimehoshi/ebiten/audio"
-	"github.com/hajimehoshi/ebiten/audio/vorbis"
+	"github.com/hajimehoshi/ebiten/audio/mp3"
 	"github.com/hajimehoshi/ebiten/audio/wav"
 	"github.com/hajimehoshi/ebiten/ebitenutil"
 )
@@ -36,7 +36,7 @@ const (
 
 	// This sample rate doesn't match with wav/ogg's sample rate,
 	// but decoders adjust them.
-	sampleRate = 48000
+	sampleRate = 44100
 )
 
 var (
@@ -113,11 +113,11 @@ func NewPlayer(audioContext *audio.Context) (*Player, error) {
 	if err != nil {
 		return nil, err
 	}
-	oggF, err := ebitenutil.OpenFile("_resources/audio/ragtime.ogg")
+	mp3F, err := ebitenutil.OpenFile("_resources/audio/game2.mp3")
 	if err != nil {
 		return nil, err
 	}
-	s, err := vorbis.Decode(audioContext, oggF)
+	s, err := mp3.Decode(audioContext, mp3F)
 	if err != nil {
 		return nil, err
 	}
@@ -136,6 +136,9 @@ func NewPlayer(audioContext *audio.Context) (*Player, error) {
 		volume128:    128,
 		seCh:         make(chan []uint8),
 	}
+	if player.total == 0 {
+		player.total = 1
+	}
 	player.audioPlayer.Play()
 	go func() {
 		s, err := wav.Decode(audioContext, wavF)